Attachment 11
feet). This point must be marked on the pavement with a "Nm" above the point at 12.3 meters
(41 feet) radially from the center point and " 'Month' 'Year' " below the point at 11.7 meters(39
feet) radially from the centerpoint. The date will reflect when the magnetic north was
established by a field magnetic survey. The markings will consist of 300 millimeter (12 inch)
high block numerals with 75 millimeter- (3-inch-) wide orange point stripes. The bronze
marker will be stamped with "Magnetic North - Established 'Day' 'Month' 'Year'" and
"Declination - 'Degrees' 'Minutes'."
A11.6.2.1.3. Compass Rose Control Points. Twenty-four (24) control points will be provided
at 7.5 meters (25 feet) radially from the centerpoint beginning at true north and then every 15
degrees (15). These points will consist of bronze markers accurately grouted in place. Each of
these points will be stamped with their true azimuth (for example 15NT).
A11.6.2.1.4. Magnetic Compass Calibration Stripes. These stripes are set at magnetic
directions from the corresponding true compass rose control point at every 15 degrees (15). A
150 millimeter- (6-inch-) wide orange stripe will be painted radially from the center of the pad
for 7.5 meters (25 feet) for each of the 24 compass rose control points. Each stripe will be
bordered by a 40 millimeter- (1-inch-) wide white stripe. At a distance of 8.2 meters (27 feet)
from the center of the pad, in white 600 millimeter- (24-inch-) high block numerals with 0.15-
meter- (6-inch-) wide orange paint stripes, paint the azimuth of each stripe as measured from
magnetic north. Each orange numeral will be bordered by a 40 millimeter- (1-inch-) wide
white stripe. The layout of the compass rose is detailed in Figure A11.2.
A11.6.2.2. Existing CCPs. For existing CCP, the surveyor will be required to check the alignment
of the magnetic north control point and adjust it if necessary. If the average magnetic declination,
as determined by a magnetic field survey described in paragraph A11.5.1. above, differs by more
than 0.5 degrees (30') from what is marked on the CCP, then the CCP must be re-calibrated. First,
all magnetic markings must be removed from the pavement. Then the magnetic north control point
marker must be removed and reset to the correct position as described above for a new CCP. The
compass rose markings are then laid out and marked as described above for a new CCP.
A11.7. Siting Considerations:
A11.7.1. Separation Distances. To meet the magnetically quiet zone requirements and prevent outside
magnetic fields from influencing the aircraft compass calibration, all efforts possible will be taken to
make sure that the center of the pad meets the minimum separation distance guidelines.
A11.7.1.1. The minimum recommended separation distances are as follows:
A11.7.1.1.1. 70 meters (230 feet) to underground metal conduits, metal piping (including
reinforced concrete pipes), or similar items.
A11.7.1.1.2. 85 meters (280 feet) from the edge of any pavement that is not specifically
designed and built for CCP operations.
A11.7.1.1.3. 150 meters (500 feet) to underground alternating current (AC) power lines
(including runway/taxiway edge lighting).
A11.7.1.1.4. 185 meters (600 feet) to overhead steam lines; overhead conduits or metal piping;
overhead AC power lines; any AC equipment; the nearest edge of any railroad track; the
nearest fire hydrant; and the nearest portion of any building.
A11-5
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